Phase sensitive differential polarimetry technique and apparatus
AssigneeThe Johns Hopkins University
InventorsArnold L. Newman, William D. Stanbro
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Abstract
A differential polarimeter is disclosed for detecting changes in optical rotation between a test cell and reference cell. The test cell contains a fluid sample exposed to an analyte specific enzyme; the reference cell contains a fluid sample not exposed to the enzyme. To enhance the sensitivity of the system a phase sensitive differential polarimetric technique is taught. In this technique, the phase difference between two resulting sinewave voltages is a measure of analyte concentration.
Claims12
A device for detecting the presence of an analyte in a fluid comprising:
- an enzyme adapted to react with the analyte changing the optical rotation of the analyte;
- means forming a first beam of polarized light directed to a test cell containing a sample of the fluid that has been exposed to said enzyme;
- means forming a second beam of polarized light directed through a reference cell containing a sample of the fluid which has not been exposed to said enzyme;
- and,
- a differential analyzing means for comparing the relative optical rotation of said first and second beams after they pass through said test and reference cells respectively, thereby indicating the concentration of the analyte in the fluid.
A device for detecting the presence of an analyte in a fluid comprising:
- an enzyme adapted to react with the analyte changing the optical rotation of the analyte;
- means forming a first beam of polarized light directed through a test cell containing a sample of the fluid that has been exposed to said enzyme;
- means forming a second beam of polarized light directed through a reference cell containing a sample of the fluid that has not been exposed to said enzyme;
- a rotational means for passing the first and second beams through respective first and second essentially synchronous rotating polarization planes;
- a first detection means for detecting the amplitude of the first beam that passes through the rotational means, thereby providing a sinusoidal voltage V.sub.1 ;
- a second detection means for detecting the amplitude of the 2nd beam that passes through the rotational means, that produces a sinusoidal voltage V.sub.2 ;
- a phase detector means for detecting the phase difference between sinusoidal voltage V.sub.1 and V.sub.2, the phase difference is indicative of analyte concentration.
A device for detecting the presence of an analyte in the fluid comprising:
- an enzyme adapted to react with the analyte changing the optically rotation of the analyte;
- a test cell containing a sample of the fluid which is exposed to said enzyme;
- a reference cell containing a sample of the fluid which has not been exposed to said enzyme;
- a means for generating a first and second beam of polarized light adapted to pass through said first and second cell, respectively, wherein said first and second beam of polarized light each have a plane of polarization that is rotated in an essentially synchronize manner;
- and,
- a differential analyzing means optically coupled to the first and second beams after they pass through said test and reference cells, respectively, for comparing the relative phase shift between said first and second beams, thereby indicating the concentration of analyte in the fluid.
Dependencies are inferred from the claim text.